I've recently gotten a shiny new Push 2 through the trade-in program. It works great.

However, I notice that the switches surrounding the screen (and some of the interface buttons) seem to be assembled inconsistently. Some of them have a nice easy push and a solid mechanical "click." But others, especially the ones near the middle of the screen, have to be pushed quite a bit more deliberately and have less of a "click" and more of a "bump", probably because they have to be pushed further through the rubber.

I think what's happened is that the circuitboard they're mounted to isn't entirely flat. It certainly works fine - all the features are there, and the pad grid appears to work very well - but that sort of mechanical inconsistency seems out of place with a device as otherwise premium-built as the Push 2.

Have other Push 2 owners noticed this? Is this fairly common or is there a chance there's something wrong with my unit?

The buttons usually aren't completely consistent but it's not an issue.
If you feel like it's really a problem on your unit I encourage you to return it back to the store, or to contact support@ableton.com if you bought it here.